1. Field of the Invention
The present invention relates to an ink recorder including a sealing member adapted to sealably close therewith an opening portion of an ink supply passage extending from an ink storing section in which ink to be injected is stored and more particularly to an ink recorder serving as, e.g., an ink storing section, a recording head or an ink supply unit.
2. Description of the Prior Art
As is well known in the art, a number of tubes are used for an ink jet recording apparatus so as to reliably supply ink to an ink jet recording head via a predetermined supply passage. However, since it is difficult to turnably extend these tubes in the ink jet recording apparatus within the range defined by a comparatively short distance, a member molded of a synthetic resin and including a bent ink passage is sometimes used for the ink jet recording apparatus. In addition, since an ink supply passage formed in the foregoing member has a small cross-sectional area, an opening portion should be formed at a certain location on the ink supply passage so as to allow air to be vented to the outside therethrough during a molding operation.
Usually, however, since the opening portion is located at the intermediate position of the ink supply passage, it should sealably be closed by employing some means for the purpose of preventing ink from leaking through the opening portion. To this end, either the process of thermally fusing a sealing member such as a cover member or the like to the opening portion or the process of sealably closing the opening portion with an adhesive has been hitherto employed. The aforementioned kind of opening portion in the ink supply passage is formed on an ink tank serving as an ink accommodating section, a pump for supplying ink or a complicated ink conduction passage.
With a sealing step practiced using the conventional sealing member employable for the opening portion as mentioned above, however, there appear problems in that production becomes complicated, with each sealing member being produced with variations from product to product, or the sealing member inadequately adheres to the opening portion and ink is undesirably evaporated. In addition to the aforementioned problems, there is still another problem that a recording operation cannot stably be performed even though the sealing member is simple in structure. Furthermore, it is not desirable to take expensive steps to correct this point, particularly from the viewpoint of durability of the sealing member, because a small location to be assumed by the sealing member is undesirably enlarged in structure, resulting in appearance of a problem that the whole ink recorder cannot be designed and constructed with smaller dimensions. It goes without saying that leakage of ink through the opening portion induces fluctuation of pressure, causing a recording operation to be inconveniently performed. In addition, the interior of the ink jet recording apparatus is stained with the leaked ink.
It is desirable for the ink jet recording apparatus to properly cope with various environmental variations at all times. However, such measures have not heretofore been taken for the ink jet recording apparatus so as to allow the stably sealed state of the opening portion to be maintained at an inexpensive cost for a long time under any environmental condition.